1. Field of the Invention
The present invention relates to a method for screening wooden chips or similar particular materials and to a screening apparatus for carrying out the method.
A known screening apparatus includes a chute arranged upon a bottom frame, the chute being provided with an upper bottom which includes a screening grid consisting of mutual parallel screening rods, and is vibrated relative to the frame by a vibrating device. The bottom frame is provided with longish carrier elements, which are arranged to project upwardly between the screening rods so that gaps are created between the rods. When the chute is vibrating, e.g., is oscillating in a plane in its longitudinal direction, the screening rods perform a to-and-fro movement relative to the carriers, by which particulate materials with a piece size less or equal to the width of the gaps fall through the screening grid and are be picked up on a lower bottom arranged on the chute.
It has appeared that the known device has a range of application limits to certain kinds of particulate materials and that it has a limited capacity. Thus it is desired to widen the range of application of the apparatus and to increase the capacity within given limitations.